Upgrading uwosh.pfg.d2c
=======================

If you were using an early version of D2C (pre-1.0) and you are
upgrading to 1.0 or later, a significant difference is that 1.0 and on
use BTrees as the basis for the D2C save data adapter, in order to
work with large numbers of contained objects.

If you encounter error messages relating to BTrees, you will want to
go into the ZMI, portal_setup, Upgrades tab, choose the
"uwosh.pfg.d2c:default" profile, and check at least the box for
"Upgrade uwosh.pfg.d2c to 1.0" then press the Upgrade button.  That
will upgrade all your old non-BTree D2C save data adapters to using
BTrees. 
